Many different types of networked computing systems support the remote retrieval of data files. These data files are offered by a remote server to a set of local clients. The local clients download the data files and maintain local copies of the data files. After downloading the data file the local client may periodically access that local copy of the data file, but the copy on the remote server may have changed since the last access. If the local client seeks to utilize the most current version of the data file, then the local client will check with the remote server to determine whether the data file is current each time it is needed. To avoid having to re-load the file, a request is sent to the remote server with the time stamp of the local copy which is then utilized to determine whether or not the remote copy is identical to the local copy. The time stamp of the local copy is compared with the time stamp of the remote copy and if they match it is assumed that the two files are identical. In this manner, downloading the remote copy can be avoided and the resources necessary to obtain the remote copy do not have to be tied up.
Similar systems utilize checksums in place of time stamps. The checksum is obtained by processing a data file to obtain a value that is relatively small in size but is essentially unique to the file that it is generated from. In other words, a checksum function is unlikely to generate the same result value on any two data inputs regardless of the size or the variation between the two. These checksum values have been utilized in place of the time stamp by creating a checksum value for a local copy and sending it to the server where it is compared with the remote copy. If the two match then it can be assumed that the remote copy and the local copy are identical. If they do not match then the remote copy is sent to the requestor.